Guarantees things will happen, even if an error is thrown or the process is killed:

var guarantor = require("guarantor")

guarantor(function(callback, status) {

  yourCleanupFunction(callback)

  if (status == 0) {
    console.log("Log an error here if you were hoping to do something asynchronously. Node is exiting.")
  }
}

Test the three code paths:

Run npm test and wait for an error to be thrown.

Run npm test and hit ctrl+c.

Run npm test normal exit to see the warning we throw when we don't have time to wait for the callbacks.